Plaster mixing machine



July 28; 1931.

H. S-JOHNS PLASTER MIXING MACHINE Filed May 28. 1930 2 Sheets-Sheet l July 28, 1931. Hfs. JoHNs 1,316,588

PLASTER MIXING MACHINE Filed May 28. 1950 2 Sheets-Sheet 2 fnuentaz" "1 ttameys.

Patented July 28, 1931 UNITED STATES HENRY STINSON JOHNS, OF HAMILTON, ONTARIO,

ONTARIO PLASTER MIXING MACHINE Application filed. May l28, 1330. Serial No. 456,653.

My invention relates'to improvements in machines for mixing 'plaster and the like, andthe object of my invention is to construct a machine which is particularly adapt- 45 ed for mixing materials for tinted plasters andalso dry plaster mixtures composed of Various granular substances.

The object of my invention is to utilize ya standard horizontal revolving drum and to furnish such drum interiorly with spiral means for carrying the mixture towards the central portion of the drum, and also to furnish the drum with other rotary mixing members tending to carry themixture in opposite directions to itsl movement under the influence of the spiral means.

A further object of my invention is to furnish a mixture filling and removal trap door .in the drum and'tosurround the trap door containing portion of the drum with a shield ,in Orderfto facilitate the ready Arel.movalof the mixture from the drumas shall .be yhereinafter explained.4 i

invention relates to improvements in mixingmachines all as hereinafter moreparticularly described and illustratedin the accompanying drawings in which:

` Fig. lis a plan viewvof my device, part of thedrum being broken away.

Fig. .2 is a vertical cross sectional view taken through the line 2-2 Fig. 1.

Fig. r3 isa perspective ,viewof a fragmentary portion of the druniand trap door.

4is an enlarged siden elevational view partly. irl-section of a pair of mixingmembers.

Fig. 5 is a perspectiye View ofone of my spademixers, and

' Fig. 6 is a perspective view of one of my trowel mixers.

Like characters of reference indicate corresponding parts in the different views in the drawings.

My mixer comprises a` horizontal rotary drum 1 freely carried upon a central hori- Zontal rotary shaft 2 mounted Vin a pai-rof end bearings 3 Whichiare carried upon supporting brackets t so that the Vdrum 1s supported some little distance above the floor upon which the machine is supported.

lthe shaft 2 I furnish a shaft. 4rods 16 Extending in parallel relation to the drum 1, I furnish a driving shaft 5 which ,is sup;- ported in a pair of end :bearings 6 "also carried upon the brackets upon one end of the shaft2 and meshing with a pinion 8 secured to thecorre'sponding'end of the driving shaft 5. i i' In the Ivicinityof the other end offthers'hajft 5 I furnish a extending through thebea'ring and carrying` upon its outer end a pairof beltlpulleys 10 and 11, the pulleyflO` being an idlerpulley and the pulley 11 securedt'othe sleeve'.` 12is a gear secured to Ithe adjacent 'end' drum 1 and meshing with a pinion 13 uponthe inner end' of the sleeve 9. .Uponthe end of the shaft 5 protrudingv from thesleeve 9 I position apairof beltpulleys 14 and ,15, 1 4 being an idler pulley u and the Vpulley* l5 being secured to the shaft.

Interiorly of the drum 1 and carried upon plurality of radially extending rods 16 which extend from a plurality of blocks 17 clamped'and keyedto the The Outer ends 18 of the alternate secured 2O which convolute in Opposite directions, each spiral ribbon occupying one half ofthe drum'. in the ends of the rods16. yThe rods 16 also carrymy spade and trowel members 22. and 23, such members being of the' formillustrated in Figures 5 and 6. Each spade 22. is

formedwith a vcentral sleeve24toreceive a rod, aset screw 25 being provided whereby the spade can be secured at vany desiredangle upon its rod. The trowel Ymembersl23 are each .formed with lugs26 by means of which they are secured to i of the rods16 `through the `medium of pins 28 which extend Ythrough the'lugs and blocks. Each of the blocks27is formedwith a pair oflugs 29 .having ythreaded orifices vtherein through which adjustingscrews ,30vextend and bear against .the faces'of thetrowels whereby vthe angularity of such trowels may be adjusted. .i

In the central portion of the drum 1, .I

sleeve 9 thereon, such: sleeve blocks 27 upon the ends CANADA, ASSIGNOR TO BANCROFT L1. 7 is a gear carried carry a pair of spiral ribbons 19.and

vThe ribbons extend throughslots" 21 provide a rectangular trap door 31 whichA is carried upon a rectangular flanged frame 32 surrounding the mixture filling and emptying orifice 33 in the drum. 'Ihis trap door can be removably secured in position in the frame in any desirable manner, as illus trated in the drawings I furnish a pair of studs 34 projecting from one edge of the trap door adapted to be contained within a air of orifices 35 in the corresponding edge of the door frame 32, and extending through the opposite edge 'of the trap door I furnish a U shaped bolt 36 which removably extends into the orifices 37 in the corresponding edge of the door frame. The bolt 36 is heldin engagement with the orifices 37 by a spring 38 extending between the end of the bolt and the edge of the trap door, the bolt being withdrawn against the resiliency of the spring 38 out of the orifices 37 when it is desired to remove the trap door. Surround-v ing the central. portion of the drum 1 in which the trap door is contained I mount a substantially circular shield 39 which is formed with an opening 40 in its top, and a chute opening 41 in its bottom which extends through the floor 55; a hopper or other suitable receptacle being positioned under- I neath thefloor 55.

vWhen my mixer is being filled with the various dry plaster ingredients, the drum 1 is in theposition illustrated in Figures 1 and 2, the trap door 31'being uppermost underneaththe opening 40 in the shield. The trap door is opened and the mixture deposited in the drum, after which the trap door is locked in place and the mixer is ready for operation'.

The four pulleys 10, 11, 14 and 15 carry a pair ofrshifting driving belts (not shown) and when the mixer is stopped the pair of belts run upon t-he idler pulleys 14 and 10, and when it is desired to run the mixer the belts are shifted over onto the driving pulleys 15 and 11; the belts run in opposite directions so that the driving pulleys also run in opposite direc-tions. If the driving pulley 15 is rotating in a clockwise direction the shaft 5 to which it is secured and pinion 8 will also rotate in a clockwise direction with the consequent anti-clockwise rotation of the gear 7, shaft 2, spiral ribbons 19 and 20, and the mixing spades and trowels. As the driving pulley 11 is rotated in an anti-clockwise direction,lthe sleeve 9 and pinion 13 will also rotate in an anti-clockwise direction with. the consequent clockwise rotation of the gear 12 and the drum Y1. It will be therefore understood that the ydrum rotates in an opposite direction to the mixing members contained therein.

,The convolutions of the spiral ribbons 19 and 20are such that their rotative action carries the material contained within the drum towards itscentre and the inclination of the spade members 22 such that spade members have a tendency to throw the material back towards the ends of the drum. The

trowel members 423 which can be adjusted so that they lie rather close to the inner surface of the drum prevent the material from packing, in that they bear down on the agitated material lying in the bottom of the drum to break up any lumps contained therein and work the materials in together. y

Vhen the mixer has been run for some five or ten minutes which is the average time for thoroughly mixing all the ingredients of any dry plaster mixture or the like, the belt upon the driving pulley 11 is shifted across to the idler pulley 10, so that the drum 1 is free andnot positively rotated. Upon the other end of the drum to the gear 12 I furnish a pawl member 42 which projects therefrom and engages the bracket 4 during each rotation of the drum 1. This pawl however is so mounted that it permits the drum to. rotate in its mixing direction of rotation, but engages the bracket 4 and prevents it:v from rotating in the opposite direction. `When the driving belt is moved from'the pulley 11 to the pulley 10 as previously explained, the drum 1 being free will be re versed in movement and carried around through the friction of the mixing members until the pawl 42 engages the bracket, when the drum will stop. The pawl is so positioned in regard to the trap door that when this engagement occurs the trap door will beunderneath the opening 40 in the shield 39. The trap door is then removed and the driving belt moved back from the idler pulley 10 onto the driving pulley 11 when the drum 1 will recommence its normal rotativeV movement. l

As the material is carried to the centre of the drum by the spiral ribbons 19 and 20 and the trap door is open, it will be obvious that each time the drum rotates and the trap i door lies under the opening in the shield,

the rotation of the mixing members then being brought to a standstill.

From the foregoing description it will be apparent that I have devised a particularly simple and effective type of mixer wherein the ingredients are thoroughly and completely mixed in a very short period of time through the provision of the opposed agitating means herebefore described and also that I have provided an operating means wherebywthe mixing drum can be very readily filled and emptied.

lVhat I claim as my invention is:

l. In a material mixing machine, a hori- Zontally rotatable drum, driving* means for rotating the drum in one direction, a central shaft Within the drum independently rotated in the opposite direction, a trap door positioned substantially centrally of the drum, a

pair of spiral members extending interiorly of the drum and convolving in opposite directions to the vicinity of the trap door, and a plurality of spade members also carried by the shaft and extending through the spiral members, said spade members being oppositely inclined to the convolutions of the spiral members through Which they extend, and a shield surrounding the portion of the drum containing the trap door and formed With a material inlet orilice in its top and a material discharge orice in its bottom.

2. In a material mixing machine, a horizontally rotatable drum, driving means for rotating the drum in one direction, a central shaft Within the drum independently rotated in the opposite direction, a trap door positioned substantially centrally of the drum, a pair of spiral members extending in teriorly of the drum and convolving in opposite directions to the Vicinity of the trap door, and means permitting the drum rotation in one direction but restraining it against rotation in the opposite direction in a position with the trap door uppermost, a shield surrounding the centre of the drum and formed With an orifice in its top, and a chute formed in the bottom of the shield across the upper end of Which the trap door passes.

HENRY STINSON JOHNS. 

